view test/testdraw2.c @ 4590:1ad70fb49fcb

Fix so many things that there is little place in this column to list them all but the result is that blending modes just work now for drawing primitives. Fixes involved: 1. Fix handling of alpha channel when SDL_BLENDMODE_NONE is set. 2. Make xrendercolor use floating-point values for color channels and then convert to 16 bit ints. 3. Fix handling of visuals in SDL_x11modes.c so that a 32 bit ARGB visual is used. 4. Fix the background pixel value in SDL_x11window.c so that the window background has an alpha value of 0xFF and not 0.
author Sunny Sachanandani <sunnysachanandani@gmail.com>
date Fri, 09 Jul 2010 21:36:41 +0530
parents 64ce267332c6
children 27ab20a36eba
line wrap: on
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/* Simple program:  draw as many random objects on the screen as possible */

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

#include "common.h"

#define NUM_OBJECTS	100

static CommonState *state;
static int num_objects;
static SDL_bool cycle_color;
static SDL_bool cycle_alpha;
static int cycle_direction = 1;
static int current_alpha = 255;
static int current_color = 255;
static SDL_BlendMode blendMode = SDL_BLENDMODE_NONE;

void
DrawPoints(SDL_Window * window)
{
    int i;
    int x, y;
    int window_w, window_h;

    /* Query the sizes */
    SDL_GetWindowSize(window, &window_w, &window_h);

    SDL_SetRenderDrawBlendMode(blendMode);
    for (i = 0; i < num_objects * 4; ++i) {
        /* Cycle the color and alpha, if desired */
        if (cycle_color) {
            current_color += cycle_direction;
            if (current_color < 0) {
                current_color = 0;
                cycle_direction = -cycle_direction;
            }
            if (current_color > 255) {
                current_color = 255;
                cycle_direction = -cycle_direction;
            }
        }
        if (cycle_alpha) {
            current_alpha += cycle_direction;
            if (current_alpha < 0) {
                current_alpha = 0;
                cycle_direction = -cycle_direction;
            }
            if (current_alpha > 255) {
                current_alpha = 255;
                cycle_direction = -cycle_direction;
            }
        }
        SDL_SetRenderDrawColor(255, (Uint8) current_color,
                               (Uint8) current_color, (Uint8) current_alpha);

        x = rand() % window_w;
        y = rand() % window_h;
        SDL_RenderDrawPoint(x, y);
    }
    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
}

void
DrawLines(SDL_Window * window)
{
    int i;
    int x1, y1, x2, y2;
    int window_w, window_h;

    /* Query the sizes */
    SDL_GetWindowSize(window, &window_w, &window_h);

    SDL_SetRenderDrawBlendMode(blendMode);
    for (i = 0; i < num_objects; ++i) {
        /* Cycle the color and alpha, if desired */
        if (cycle_color) {
            current_color += cycle_direction;
            if (current_color < 0) {
                current_color = 0;
                cycle_direction = -cycle_direction;
            }
            if (current_color > 255) {
                current_color = 255;
                cycle_direction = -cycle_direction;
            }
        }
        if (cycle_alpha) {
            current_alpha += cycle_direction;
            if (current_alpha < 0) {
                current_alpha = 0;
                cycle_direction = -cycle_direction;
            }
            if (current_alpha > 255) {
                current_alpha = 255;
                cycle_direction = -cycle_direction;
            }
        }
        SDL_SetRenderDrawColor(255, (Uint8) current_color,
                               (Uint8) current_color, (Uint8) current_alpha);

        if (i == 0) {
            SDL_RenderDrawLine(0, 0, window_w - 1, window_h - 1);
            SDL_RenderDrawLine(0, window_h - 1, window_w - 1, 0);
            SDL_RenderDrawLine(0, window_h / 2, window_w - 1, window_h / 2);
            SDL_RenderDrawLine(window_w / 2, 0, window_w / 2, window_h - 1);
        } else {
            x1 = (rand() % (window_w*2)) - window_w;
            x2 = (rand() % (window_w*2)) - window_w;
            y1 = (rand() % (window_h*2)) - window_h;
            y2 = (rand() % (window_h*2)) - window_h;
            SDL_RenderDrawLine(x1, y1, x2, y2);
        }
    }
    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
}

void
DrawRects(SDL_Window * window)
{
    int i;
    SDL_Rect rect;
    int window_w, window_h;

    /* Query the sizes */
    SDL_GetWindowSize(window, &window_w, &window_h);

    SDL_SetRenderDrawBlendMode(blendMode);
    for (i = 0; i < num_objects / 4; ++i) {
        /* Cycle the color and alpha, if desired */
        if (cycle_color) {
            current_color += cycle_direction;
            if (current_color < 0) {
                current_color = 0;
                cycle_direction = -cycle_direction;
            }
            if (current_color > 255) {
                current_color = 255;
                cycle_direction = -cycle_direction;
            }
        }
        if (cycle_alpha) {
            current_alpha += cycle_direction;
            if (current_alpha < 0) {
                current_alpha = 0;
                cycle_direction = -cycle_direction;
            }
            if (current_alpha > 255) {
                current_alpha = 255;
                cycle_direction = -cycle_direction;
            }
        }
        SDL_SetRenderDrawColor(255, (Uint8) current_color,
                               (Uint8) current_color, (Uint8) current_alpha);

        rect.w = rand() % (window_h / 2);
        rect.h = rand() % (window_h / 2);
        rect.x = (rand() % (window_w*2) - window_w) - (rect.w / 2);
        rect.y = (rand() % (window_h*2) - window_h) - (rect.h / 2);
        SDL_RenderFillRect(&rect);
    }
    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
}

int
main(int argc, char *argv[])
{
    int i, done;
    SDL_Event event;
    Uint32 then, now, frames;

    /* Initialize parameters */
    num_objects = NUM_OBJECTS;

    /* Initialize test framework */
    state = CommonCreateState(argv, SDL_INIT_VIDEO);
    if (!state) {
        return 1;
    }
    for (i = 1; i < argc;) {
        int consumed;

        consumed = CommonArg(state, i);
        if (consumed == 0) {
            consumed = -1;
            if (SDL_strcasecmp(argv[i], "--blend") == 0) {
                if (argv[i + 1]) {
                    if (SDL_strcasecmp(argv[i + 1], "none") == 0) {
                        blendMode = SDL_BLENDMODE_NONE;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "mask") == 0) {
                        blendMode = SDL_BLENDMODE_MASK;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "blend") == 0) {
                        blendMode = SDL_BLENDMODE_BLEND;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "add") == 0) {
                        blendMode = SDL_BLENDMODE_ADD;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "mod") == 0) {
                        blendMode = SDL_BLENDMODE_MOD;
                        consumed = 2;
                    }
                }
            } else if (SDL_strcasecmp(argv[i], "--cyclecolor") == 0) {
                cycle_color = SDL_TRUE;
                consumed = 1;
            } else if (SDL_strcasecmp(argv[i], "--cyclealpha") == 0) {
                cycle_alpha = SDL_TRUE;
                consumed = 1;
            } else if (SDL_isdigit(*argv[i])) {
                num_objects = SDL_atoi(argv[i]);
                consumed = 1;
            }
        }
        if (consumed < 0) {
            fprintf(stderr,
                    "Usage: %s %s [--blend none|mask|blend|add|mod] [--cyclecolor] [--cyclealpha]\n",
                    argv[0], CommonUsage(state));
            return 1;
        }
        i += consumed;
    }
    if (!CommonInit(state)) {
        return 2;
    }

    /* Create the windows and initialize the renderers */
    for (i = 0; i < state->num_windows; ++i) {
        SDL_SelectRenderer(state->windows[i]);
        SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
        SDL_RenderClear();
    }

    srand(time(NULL));

    /* Main render loop */
    frames = 0;
    then = SDL_GetTicks();
    done = 0;
    while (!done) {
        /* Check for events */
        ++frames;
        while (SDL_PollEvent(&event)) {
            CommonEvent(state, &event, &done);
            switch (event.type) {
            case SDL_WINDOWEVENT:
                switch (event.window.event) {
                case SDL_WINDOWEVENT_EXPOSED:
                    SDL_SelectRenderer(SDL_GetWindowFromID(event.window.windowID));
                    SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
                    SDL_RenderClear();
                    break;
                }
                break;
            default:
                break;
            }
        }
        for (i = 0; i < state->num_windows; ++i) {
            SDL_SelectRenderer(state->windows[i]);
            SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
            SDL_RenderClear();

            DrawRects(state->windows[i]);
            DrawLines(state->windows[i]);
            DrawPoints(state->windows[i]);

            SDL_RenderPresent();
        }
    }

    CommonQuit(state);

    /* Print out some timing information */
    now = SDL_GetTicks();
    if (now > then) {
        double fps = ((double) frames * 1000) / (now - then);
        printf("%2.2f frames per second\n", fps);
    }
    return 0;
}

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