view test/testdraw2.c @ 3469:8c5fb2a3b11d

RenderReadPixels and RenderWritePixels functions work with back buffer now and all asynchronous operations are flushed before reading or writing to backbuffer. Thanks Sam for clarification of this.
author Mike Gorchak <lestat@i.com.ua>
date Sat, 21 Nov 2009 06:17:50 +0000
parents 438ba87e9578
children 0267b8b1595c
line wrap: on
line source


/* 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_WindowID 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_RenderPoint(x, y);
    }
    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
}

void
DrawLines(SDL_WindowID 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_RenderLine(0, 0, window_w - 1, window_h - 1);
            SDL_RenderLine(0, window_h - 1, window_w - 1, 0);
            SDL_RenderLine(0, window_h / 2, window_w - 1, window_h / 2);
            SDL_RenderLine(window_w / 2, 0, window_w / 2, window_h - 1);
        } else {
            x1 = rand() % window_w;
            x2 = rand() % window_w;
            y1 = rand() % window_h;
            y2 = rand() % window_h;
            SDL_RenderLine(x1, y1, x2, y2);
        }
    }
    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
}

void
DrawRects(SDL_WindowID 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) - (rect.w / 2);
        rect.y = (rand() % window_w) - (rect.h / 2);
        SDL_RenderFill(&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_RenderFill(NULL);
    }

    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(event.window.windowID);
                    SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
                    SDL_RenderFill(NULL);
                    break;
                }
                break;
            default:
                break;
            }
        }
        for (i = 0; i < state->num_windows; ++i) {
            SDL_SelectRenderer(state->windows[i]);
            SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
            SDL_RenderFill(NULL);

            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;
}

/* vi: set ts=4 sw=4 expandtab: */